Answer:
I suck.
Born of sorrow, grows with age, you need a lot to be a sage. What is it?
I am just two and two. I am hot. I am cold. I am the parent of numbers that cannot be told. I am a gift beyond measure a matter of course. I am given with pleasure when taken by force.
You hold my tail while I fish for you. What am I?
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board I'm often described like a mop.
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.